-be sure to "jostle" each door while it is open and listen for standing water sloshing around in them. Some complaints about water accumulating inside the rear doors (most complaints were rear right)
-open the rear hatch and feel around real well for water near where the carpet goes under the plastic on the sides and rear... I have seen a number of people whos rear hatch leaks through the rubber boot that is to protect all the wires going through the top hinge area.
-cracked dash is a huge one...
-if you are in the denali, be sure that the cup holder and console in front of the cup holder, both of those spring loaded covers break fairly easily because it is cheap plastic. make sure both of those work, as that entire piece is not cheap.
-there has been a few issues with some of the power seat functions, check that all of those are working properly.
-if you are interested in using on star, check that out.
-be sure they include a SPARE key and fob with the sale.
-if it has navigation, check the last few addresses to see if you can get an idea of where it came from... of course there are exceptions, but geographic areas can help predict the previous owners, weather exposure, driving habits etc...
-if you are looking at 07s and even 08s... it may be worth checking to see if it is the original battery and alternator. You may not be able to tell, but most likely you will... I know a lot of people have had to replace their batteries and have had alternator issues... (just from a search on this forum when I had to do mine!)
-obviously, tires at 91k could be next to new or nearly bald...
sorry if some of this seems silly, but I know how my mind wanders when I am eyeing up a new car... you forget about the things you SHOULD be focused on!
Good luck.
